The present invention relates to an electro-luminescent light and shield for use in the illumination and display of an electronic device.
Electro-luminescent lights (hereafter EL) are used in the illumination of the key button from its rear side and the illumination of the display which carries out all kinds of display operations. Since Els represent a thin and relatively bright light source, they have often been used in recent years particularly in electronic devices where small size and thinness is desirable. However it is necessary to provide a solution to the noise and vibration generated by those Els which emit light due to the supply of a high voltage alternating current at the level of 600 HZ and 150V.
Up until the present time, an interference material has been provided in the EL as a solution to vibration problems. However as regards noise, due to the fact that it was rare for the electronic circuits to be in close proximity to the EL, no particular problem arose and no solution has been advanced. However as shown by JP-A-SHO-62-15713 and JP-A-HEI-9-93324, in an electronic device in which small size and thinness are desirable, as the electronic components are installed in high density, the printed circuit board is sometimes in close proximity to the EL. Hence the high voltage alternating current supplied to the EL excites the electronic circuits on the printed circuit board and the problem arose that noise was generated. In particular when the EL illuminates the key button, there is the problem that noise is superimposed on the on-off signal of the key button and an error signal may be generated.
The present invention is proposed in order to solve the above problems and has the purpose of providing an EL and a shield device therfor which prevents the generation of noise in a circuit of a printed circuit board which is disposed in close proximity to the EL.
The structure of the shield of the electro-luminescent light of the present invention comprises a printed circuit board on which is mounted the electronic components, an electro-luminescent light which is placed in close proximity to the printed circuit board and illuminates due to the application of a high voltage alternating current, and a shield member which is provided between the electro-luminescent light and the printed circuit board and shields the high voltage alternating current which is applied to the electro-luminescent light.
In this way, it is possible to prevent the generation of noise in the electronic circuit on the printed circuit board.
The structure of the shield of the electro-luminescent light of the present invention comprises a click board on top of the printed circuit board for placing the contact points of the switches in the on-off position by the depression of a plurality of key buttons arranged in parallel and a shield member placed between the electro-luminescent light and the click board and between the electro-luminescent light and the printed circuit board.
In such a way it is possible to prevent the generation of noise in the electronic circuits on the printed circuit board, particularly noise in the on-off signals generated by the operation of the key buttons.
The structure of the shield of the electro-luminescent light of the present invention comprises a shield member constructed by a shield layer printed into the bracing seat used for fixing the click board to the printed circuit board.
Hence this structure has the advantage that it is easy to assemble a device with a shield layer.
The structure of the shield of the electro-luminescent light of the present invention comprises a shield member which is constructed by a shield layer printed onto the rear face of the electro-luminescent light.
Hence it is possible to printed the shield layer in tandem with the electro-luminescent light fabrication process.
The structure of the shield of the electro-luminescent light of the present invention comprises a shield layer printed in carbon ink.
Hence it is possible to prevent the generation of noise in the electronic circuits on the printed circuit board at a low cost.
The structure of the shield of the electro-luminescent light of the present invention comprises a shield member electrically connected to the shield line wired printed onto the printed circuit board.
Hence it is possible to again improve the effects of the shield.
The structure of the shield of the electro-luminescent light of the present invention is electrically connected by crimping an electrically conductive adhesive, which is printed onto the shield member, to the shield line on the printed circuit board.
Hence it is possible to easily perform connecting operations.
The structure of the shield of the electro-luminescent light of the present invention uses a shield member as a shield layer which is printed onto the rear surface of the electroluminescent light. Furthermore the partial regions on the peripheral edge of the electro-luminescent light are not laminated with the luminant layer which comprises the electro-luminescent light. The device is electrically connected by crimping the shield layer to the shield line on the printed circuit board through the conductive adhesive which is printed on the shield layer corresponding to the partial regions.
Hence it is possible to prevent the generation of cracks in the light generating layer.
The structure of the shield of the electro-luminescent light of the present invention comprises an electro-luminescent light which generates light due to the application of a high voltage alternating current, a holder, the face of which is formed on the shield member and which abuts with the electro-luminescent light, a positional determination member which is formed from an insulating material as a unit with the electro-luminescent light, abuts with the holder, and determines the position of the electro-luminescent light so that the end face of the electro-luminescent light does not come into contact with the surface of the holder, and a printed circuit board which is disposed in close contact with the holder and on which are mounted the electronic circuits.
Hence each layer of the end face of the electro-luminescent light does not come into contact with the shield member on the surface of the holder and the shield effect is not diminished.
The structure of the shield of the electro-luminescent light of the present invention comprises an electro-luminescent light which generates light due to the application of a high voltage alternating current, a crystal display element which is illuminated from its rear face side by the electro-luminescent light, a flexible printed board one end of which is connected to the end of the crystal display element and on the face of which are mounted the electronic circuit elements, a shield member formed on the rear face of the flexible printed board, and a holder which bends the flexible printed board on the rear face of the crystal display element and pushes the electro-luminescent light in an abutting state into the space between the rear face of the flexible printed board and the rear face of the crystal display element.
Hence the generation of noise in the electronic circuits on the flexible printed board can be prevented.
The electro-luminescent light of the present invention is comprised of a transference electrode, a ruminant layer, a dielectric layer and a back plate and an insulating layer disposed in that order to form multiple layers on a base film. The electro-luminescent light forms a shield layer on the insulating layer and a conductive adhesive layer on the partial regions of the peripheral edge of the shield layer.
Hence the generation of noise due to the application of a high voltage alternating current in the electro-luminescent light can be prevented.
The electro-luminescent light of the present invention is adapted so that at least the luminant layer is not laminated on the partial regions of the peripheral edge of the electro-luminescent light. A conductive adhesive layer is imprinted to those parts corresponding to the partial regions of the peripheral edge of the shield layer.
Hence the generation of cracks in the ruminant layer can be prevented.
The electro-luminescent light of the present invention is adapted so that the shield layer is formed by the printing of carbon ink on top of the insulating layer.
Hence a sufficient shield can be created at a low cost.